Hello Jennifer,
Thank you for writing to Teacher2Teacher. After searching the Internet, I
found the best resource for PPST material is Praxis, the makers of the test.
There is no mention of a practice software, but there is an explanation of
the test with some sample questions. You can download this from the Internet
or order it through the mail.
http://www.ets.org/praxis/prxtest.html#ppst
It would seem your path to find what you need will start there.
Good luck!
- Dave, for the Teacher2Teacher Service